There have been three main methods for adding an “on-hold” circuit to present day telephones; the first method utilizes a KSU or Key Service Unit in which the phones are specially designed to work with this main processing unit. The “on-hold” button is designed into the phones and is activated by pressing this button which in turn sends this activation data to the main KSU which performs the hold function. The KSU and phones are generally for larger business and because of the cost, maintenance and complex nature of programming are not used by the small business owner.
The second method for adding an “on-hold” circuit utilizes a locally “store-bought” single or multi-line phone with a hold button. A few problems arise when using this method since out of the complete population of single and multi-line phones that are available only a few will have a hold button. The few phones that do incorporate a hold button generally will put the customer on-hold, but will not give the ability to inject music and/or messages into the hold circuit while the customer is on-hold.
The third and final main method that is used for adding an “on-hold” circuit utilizes special after market devices that attach to either the incoming phone line or phone handset cord. Along with having to hardwire these devices most are not compatible with all standard phones without some type of tuning or special versions of the models that are available. When adding additional phones after the initial installation some systems require retuning because of the additional impedance created on the phone line. The methods used to place callers on-hold using these systems is not consistent; with some using special cumbersome buttons or large switch boxes hardwired to the phone line or phone cord. While others utilize the touch-tone keys on the phone to activate the hold circuit which is sometime an annoyance to the customer since they hear this tone before being put on-hold.
Conventional means and methods known today for adding and implementing an “on-hold” circuit are burdensome, expensive, time-consuming, and/or do not provide a reliable method, and thus are often not deployed into service. What is needed in the art is a reliable, expedient and cost effective method to adding an “on-hold” circuit to a “store-bought” single or multi-line phones.